In communication networks such as Internet protocol (IP) networks implemented using LSPs it may be necessary to preempt one or more lower priority LSPs during the routing of a higher priority LSP due to insufficient available bandwidth. When an LSP is preempted it may be taken down immediately causing loss of data packets until it is re-routed over a different path (i.e., a so-called hard preemption), or the preempted LSP may be allowed to remain active until it is rerouted over a different path and only then the original path of the preempted LSP is taken down thereby avoiding any loss of data packets (i.e., a so-called soft preemption).